Jacketed combustion pot with fuel and air nozzle head



Nov. 13, 1951 w. A. REED ETAL JACKETED COMBUSTION POT WITH FUEL. AND AIR NOZZLE HEAD 2 SHEETSSHEET 1 Filed April 6, 1948 INVENTORS: W/LL/AM A. REED ASCHER H. SHAP/RO ATT'Y Nov. 13, 1951 w. A. REED ET AL 2,575,070

JACKETED COMBUSTION POT WITH FUEL AND AIR NOZZLE HEAD Filed April s, 1948 2 SHEETSSHEET 2 4 INVENTORS: W/LL/AM ,4. REED H6 4 28 so BY ASGHER H. SHA P/RO arr'y Patented Nov. 13, 1 951 JACKETED COMBUSTION POT WITH FUEL AND AIR NOZZLE HEAD William A. Reed, Waban, and Ascher H. Shapiro, Arlington, Mass., assignors to the United States of America as represented by the Secretary of the Navy Application April 6, 1948, Serial No. 19,398

7 Claims. (Cl. 6039.65)

This invention relates in general to a com bustion pot which uses fuel and air in a comburent mixture and is more particularly described as power supply for torpedoes, using alcohol as the fuel and air for supporting combustion.

In controlling the temperature of combustion pots for torpedoes, it has heretofore been the practice to circulate sea water around the pot during a run which requires additional controlling apparatus for the coolant and lacks accuracy and precision which are necessary for torpedo operation. The present invention overcomes these objections by utilizing the fuel itself as a coolant in a jacket which closely surrounds the combustion chamber, and by providing an atomized mixture of primary and secondary air for supporting combustion and preventing recirculation of the combusted gases into the burning mixture.

An important object of the invention is to provide a jacketed combustion pot utilizing the fuel supplied to pot as a coolant for controlling the temperature of the pot.

A further object of the invention is to provide an atomizer for injecting the fuel and introducing both primary and secondary air supplies to support and insure more complete combustion of the fuel.

Still a further object of the invention is to provide a jacketed combustion pot with an air and fuel atomizer and a secondary air supply at one end, having parts which may be readily assembled to insure fluid tight connections and joints.

Other objects of the invention will appear in the specification and claims and will be apparent from the accompanying drawings, in which Fig. 1 is a longitudinal section of a combustion pot in accordance with the invention;

Fig. 2 is an elevational view of the injection nozzle taken on the line 2--2 of Fig. 1;

Fig. 3 is an end elevation of the injection end of the pot; and

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 3, with the atomizer omitted.

In carrying out this invention fuel is admitted to one end of a jacket surrounding a combustion chamber and is directed from the other end of the jacket to an air pressure injector into the chamber where the mixture is fired and mixed with secondary air to insure more complete combustion. and the hot gases are discharged from the end of the chamber opposite the injector.

Referring now more particularly to the drawings an inner cylindrical shell i0 is rounded inwardly at one end and connected to a reduced end fitting l2 which provides a hot gas discharge neck. Surrounding the shell and spaced therefrom is a casing preferably comprising a rounded end piece l4 secured to the fitting l2 and flush with the end thereof, and a cylindrical outer shell it. These inner and outer shells may be varied in length depending upon the installation to which they are applied which is one of the reasons for making the outer casing in two parts, varying only the length of the shell.

The inner shell l0 and the outer casing are spaced apart to provide a cooling jacket space l8 by the end piece which is fixed to the fitting l2, and by the head 20 which has an end rib 22 extending between the ends of the shells to and I6, spacing them apart and providing means for securing them to the head with flush surfaces at the inside and outside. In most of the places where the parts are secured together they are cut or beveled so that a filet of metal, angular in cross-section, may be soldered, brazed or welded in place. This method of attaching the parts is not novel but it results in fluid tight dependable joints.

Extending.around the discharge end of the casing is a fuel inlet manifold 24 communicating with the jacket s ace 18 through a number of holes 26 spaced apart around the end piece l4. Extending around the outside of the opposite end of the casing shell I6 is a fuel discharge manifold 28 communicating with the jacket space I8 through a number of openings 30 in the shell, spaced apart. and approximately opposite an inwardly rounded groove 32 in the inner shell III which thus provides a circular passage opposite the discharge manifold 28. Both manifolds 24 and 28 are relatively flat, forming a fiat, circular passage. and do not project materially outward from the casing.

Connected to the inlet manifold 24 is a fitting 34 having a threaded hollow stem for receiving a fuel restriction plug 36 threaded therein, and for attaching a fuel inlet pipe 38 by means of a gland nut 39 threaded on the outside of the stem.

The head 20 has a reduced end portion 40.

with an inside internally threaded rib 42 to receive an atomizer head 44, with an internal threaded portion 46 near the outer end to receive a threaded closing plug 48; and with a la eral o ening 50 communicating with a fuel chamber 52 between the plug 48 and the head 44.

A pipe 54 is connected at one end to the discharge 3 manifold 28 and at the other end to the opening 60 which leads to chamber 52.

At the inner side of the rib 42 is an air chamber 66 having a tubular extension 58 at one side of the head 20 forming an air inlet 60, and to which a suitable air supply may be connected. At the inner side of the air chamber isian opening 62 less in size than the opening through the threaded rib 42, so that the atomizer head 44 which has an extension 64 to fit closely into the opening 62 may be inserted from the outer end of the end portion 40 into and through the opening formed by the rib, closing the opening 62 by the extension 64. The head 44 is threaded in the rib 42 until it fits tightly or against a flange 66 at the outer side of the head.

In the outer side of the atomizer head 44 is a recess 66 forming a strainer chamuer in which a holder 12 is inserted carrying a fuel strainer 14 of the outwardly rounded tvpe, extending partially into the fuel chamber 62, and presenting a large straining area.

At the center of the extension 64 of the atomizer head 44 is a bore I6 extending into the strainer chamber and threaded at the inner end to receive an externally threaded hollow nozzle stem 18 with a slotted screw head 80 inserted from the strainer chamber. The sides of the extension 64 are holes 82 inclined inwardly toward the outer end and communicating at the outside of the extension with the air chamber 66. These holes are located intermediate the ends of the stem 18 but inclined toward and adjacent the outer free end of the stem, so that air pressure from air chamber 56 atomizes fuel discharged from the nozzle stem.

Surrounding the bore I6 the extension 64 has an inwardly inclined flange 03 in which are a plurality of air holes 84 forming communication between the air chamber 56 and the end of the combustion chamber. Fuel dischar e tubes 86 are mounted in the atomizer head 44 extendin therethrough from the fuel strainer chamber 10 and into the air holes 84 which they fit loosely with space around the tubes for air under ressure from the air chamber 56. The tubes 06 are inclined outwardly through the flange 89, radiating from the central nozzle stem 16.

Fuel is forced outwardly under pressure through the stem I0 and the tubes 66 and is more completely atomized by primary air under pressure from air chamber 56. A secondary air supply is provided to prevent recirculation of combusted gases into the burning mixture and to provide a region of low velocity air at the boundaries of the burning mixture to stabilize and pilot combustion.

In the end of the head 20 surrounding the atomizer are perforated rings 90 and 92 at an angle in the head and from each other forming an annular secondary air chamber 94 which is fed with air from the primary air chamber 56 through a plurality of holes 96 each having an air restriction plug 98 threaded therein. These rings 92 and 94 are preferably in contact at their inner peripheries and are held angularly apart at their outer peripheries by a spacer ring I00.

In the inner ring 90 are a large number of small holes I02 and in the outer ring 92 are a smaller number of larger holes I04 which admit the secondary air under reduced pressure to the outer periphery of the combustion chamber surround- I ing the atomizer.

Threaded through the wall of the head 20 at the outside of the end portion 40 is an ignition plug I06 having an inner end I00 which projects through the rings and 92, preferably terminating close to the ring 92 and within the combustion chamber, close to the zone of the reduced air pressure.

At the discharge end of the combustion chamber is an elbow (or other) fitting IIO which is secured by brazing or otherwise to the reduced end fitting I2 which forms a discharge neck for the combustion chamber.

With this construction fuel is admitted under pressure from pipe 38 through the restriction plug 36 to the inlet manifold 24. It then passes through the holes 26 to the jacket space I8, passing in a relatively thin layer between the inner and outer shells I0 and I 6, and through openings 30 in the outer shell to the discharge manifold 28. From the manifold 20 the pipe 54 conducts the fuel to the fuel chamber 52 at the end of the head, and through the strainer 14 into the strainer chamber I0.

At the same time air is admitted under pressure through the air inlet 60 to the air chamber 56, and passes outwardly therefrom into the combustion chamber through holes 82 and the bore 16 and also through the holes 84 around the central bore 16. This air under pressure assists in atomizing the fuel which is directed into the combustion chamber from the strainer chamber 10 through the nozzle stem 10 and the discharge tubes 66.

A secondary air supply under reduced pressure is directed to the air chamber 94 inside of the head 20 through restriction plug 98, from whence it passes into the combustion chamber through small holes I02 in the inner ring 90 and through larger openings I04 in the outer ring 92.

The atomized fuel is ignited by a spark plug I06, or any suitable igniting means, and burns or expands in the combustion chamber, passing therefrom through the end fitting I2 and any piping means connected therewith into any suitable pressure or power means.

The flow of the fuel through the jacket space I0 is rapid and continuous and it continuously cools the inner shell which is heated by the ignited and burning gases in the combustion chamber of the pot. Heating of the fuel increases its volatile characteristics and makes it more subject to vaporiaztion by the nozzle and pipes and under the air pressure.

While this structure is described in some detail, it should be regarded as an illustration or an example, and not as a restriction or limitation of the invention, as many changes may be made in the construction, combination and arrangement of the parts without departing from the spirit and scope of the invention.

We claim:

I. A combustion pot comprising spaced shells closed at the ends to provide a cooling jacket, inlet and discharge manifolds surrounding the outer shell and communicating with the jacket, a closing head for the shells at one end having an air chamber and a fuel chamber, means connecting the discharge manifold with the fuel chamber, and a nozzle head insertable in the closing head to separate the air and fuel chambers and having discharge tubes in the air chamber for discharging fuel into the pot with a pressure of air from the air chamber.

2. A combustion pot comprising spaced shells closed at the ends to provide a cooling jacket, inlet and discharge manifolds surrounding the outer shell and communicating with the jacket,

a closing head for the shells at one end having an air chamber and a fuel chamber, means connecting the discharge manifold with the fuel chamber nozzle means in the head to separate the air and fuel chambers and including fuel discharge tubes extending through the air chamber to atomize fuel therefrom due to primary air pressure from the air chamber, and means connected to the air chamber within the closing head to supply secondary air within the pot under reduced pressure.

3. A combustion pot comprising spaced shells closed at the ends to provide a cooling jacket,

inlet and discharge manifolds surrounding the outer shell and communicating with the jacket. 8. closing head for the shells at one end having an air chamber and a fuel chamber, means connecting the discharge manifold with the fuel chamber, nozzle means in the head to separate the air and fuel chambers and including fuel discharge tubes extending through the air chamber to atomize fuel therefrom due to primary air pressure from the air chamber, perforated rings mounted in the end of the closing head and an inner chamber formed thereby connected to the air chamber to supply secondary air into the pot .under reduced pressure, and ignition means extending through the rings to the interior of the pot and extending through the closing head to the outside thereof.

4. A combustion pot having a closing head with an opening therethrough into the pot, a partition in the opening with air and fuel chambers on opposite sides and means to supply air and fuel respectively thereto, a nozzle head insertable in the opening and engaging the partition to sionto close the air chamber from the interior of the pot, nozzle tubes extending from the fuel chamber through the air chamber and fitting loosely into the perforations to atomize the fuel by the air under pressure, and a fuel strainer in the fuel chamber in advance of the nozzle tubes accessible for insertion and removal by removing said plug.

6. In a combustion pot, a closing head having removable nozzle means therein forming fuel and air chambers, means for supplying fuel and air separately to said chambers, nozzle tubes for feeding fuel under primary air pressure from the air chamber, a secondary air chamber within the head surrounding the nozzle tubes having restricted connection means with the first air chamber and comprising partitions with graduated openings for admitting air under reduced separate the chambers, and comprising a ptrforated extension fitting the inner end of the opening into the pot, and nozzles extending through the air chamber into the perforations of the extension.

5. A combustion pot having a closing head with a reduced hollow extension, a partition in the extension with air and fuel chambers on opposite sides of the partition, means for supplying air and fuel to said chambers, a nozzle head insertable into the extension and engaging the partition to separate the chambers, a plug at the outer end of the extension to close the fuel chambet, the nozzle head having a perforated extenpressure from the secondary air chamber to the combustion pot.

7. In a combustion pot, a closing head having a central end opening with fuel and air chambers and means for supplying fuel and air separately thereto, a nozzle head insertable in the opening to separate the fuel and air chambers and having a perforated extension to fit the opening into the pot, a central nozzle tube extending from the fuel chamber through the air chamber and fitting loosely into a central opening of the extension, and other nozzle tubes around the central tube inclined angularly outward from the fuel chamber through the air chamber and into perforations of the extension so that air under pressure from the air chamber will atomize fuel from the tubes into the pot.

WILLIAM A. REED.

ASCHER H. SHAPIRO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,879,186 Goddard Sept. 27, 1932 2,000,733 Avery May 7, 1935 2,408,111 Truax Sept. 24, 1946 2,408,112 Truax et al. Sept. 24, 1946 2,434,298 Truax et al Jan. 13, 1948 2,438,247 Knudsen Mar. 23, 1948 

